1. Field of the Invention
The present invention relates to a fluid transfer apparatus, and more particularly to a fluid transfer apparatus which performs an operation by oscillating a piston. In this case, the fluid transfer apparatus is defined as an apparatus for transferring a fluid, however, includes, for example, a compressor, a pump and the like.
2. Description of the Prior Art
In a conventional fluid transfer apparatus, in the case of performing a fluid transfer in accordance with an oscillating operation using a motor, it is considered that the motor employs various structures. However, a linear motor corresponding to one of the conventional motors employs a structure in which a rotary machine is cut and opened so as to be driven in a linear manner.
In the conventional fluid transfer apparatus having the linear motor, since the linear motor is structured such that the rotary machine is cut and opened so as to be driven in a linear manner, a leakage flux between an armature and a movable element is much, and a motor efficiency is bad, so that there is a problem that it is hard to put the linear motor into practice in order to apply the linear motor to the fluid transfer apparatus requiring a high output power. Further, since a magnetic attraction force is applied to a portion between the armature and the movable element in one direction, a great load is applied to a support mechanism of the movable element, so that there is a problem that a strain is generated in the structure and various problems are generated, whereby it is hard to put the structure into practice.
In accordance with the present invention, for example, in order to make an efficiency of the conventional fluid transfer apparatus high, the structure is made such as to reduce a leakage of a magnetic flux passing through the portion between the armature and the movable element so as to reduce a magnetic attraction force generated between the armature and the movable element. An object of the present invention is to provide a fluid transfer apparatus which can improve a motor efficiency and make an output high.
In accordance with one aspect of the present invention, there is provided a fluid transfer apparatus transferring a working fluid in accordance with an oscillating movement, having a motor,
wherein the motor of the fluid transfer apparatus comprises a movable element in which magnetic poles are provided at a predetermined pitch along a moving direction and to which a piston is attached, magnetic pole teeth provided in upper and lower portions of the movable element at a predetermined pitch along a moving direction of the movable element and so as to oppose to each other via the movable element, and a coil exciting so that adjacent magnetic pole teeth and opposing magnetic pole teeth among the magnetic pole teeth form different poles,
wherein a linear motor is constituted by the movable element, the magnetic pole teeth and the coil,
wherein the movable element is oscillated by exciting the coil in accordance with a predetermined control circuit, and
wherein a fluid transfer is performed by the piston in a process of the oscillating movement.
Further, in accordance with another aspect of the present invention, there is provided a fluid transfer apparatus using a piston structured such that an oscillating stroke of the piston is changeable.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus using a piston structured such that the fluid transfer apparatus stops the piston at a predetermined position when a drive power source stops supplying.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus using a piston structured such that the fluid transfer apparatus uses a linear motor as a drive source, and the linear motor uses pistons in both sides of a movable element.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus using a piston structured such that linear motors are used in both sides of the piston.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus using a piston, further comprising a resonance spring.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus using a piston structured such that a casing is formed in a double construction, thereby achieving a cooling function due to a fluid transfer.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus, further comprising a closed loop control system constituted by a linear motor, a sensor detecting a relative displacement between the armature and the movable element and a magnetic pole, a control portion feeding back a signal of the sensor, and a power drive portion.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus, further comprising an open loop control system constituted by a linear motor, a control portion and a power drive portion.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus, further comprising a control system constituted by a linear motor, a power drive portion, and a control portion including estimating means for detecting an induced voltage of the linear motor and estimating a relative magnetic pole position between the armature and the movable element on the basis of the voltage detected value.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus, further comprising a control system comprising a linear motor, a power drive portion, and a control portion including estimating means for detecting an electric current flowing through the linear motor and estimating a relative magnetic pole position between the armature and the movable element on the basis of the current detected value.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus structured such that a plurality of armatures of the linear motor are arranged and a pitch between magnetic pole teeth of the adjacent different armatures is set to (kxc2x7P+P/M) {(k=0, 1, 2, . . . ), (M=2, 3, 4, . . . )} {in which k is a number freely selected in a range that the adjacent armatures can be arranged, M is a number of phase of the motor} when the pole pitch is set to P.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus, further comprising a switching function that any one of a battery and an external power source is employed as a power source of the fluid transfer apparatus.
Further, it is desirable to make the structure such that the linear motor is a linear motor comprising an armature and a movable element capable of moving relative to the armature, the linear motor further has one magnetic pole teeth rows which are magnetically connected to one magnetic pole of the armature and are arranged so as to be separated into a first stage and a second stage in a substantially vertical direction to a moving direction of the movable element, and another magnetic pole teeth rows which are magnetically connected to another magnetic pole of the movable element and are arranged so as to be separated into a first stage and a second stage in a substantially vertical direction to the moving direction of the movable element, the first stage of magnetic pole teeth in the one magnetic pole teeth rows and the first stage of magnetic pole teeth in the another magnetic pole teeth row are alternately arranged with respect to the moving direction of the movable element, the second stage of magnetic pole teeth in the one magnetic pole teeth rows and the second stage of magnetic pole teeth in the another magnetic pole teeth row are alternately arranged with respect to the moving direction of the movable element, and the movable element is arranged between the one and another first stage of magnetic pole teeth rows and the one and another second stage of magnetic pole teeth rows.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus using a piston structured such that the fluid transfer apparatus uses a linear motor as a drive source, and the linear motor is structured such that the stator is supported in a fixed manner and the movable element moves.
Further, in accordance with the other aspect of the present invention, there is provided a fluid transfer apparatus using a piston structured such that the fluid transfer apparatus uses a linear motor as a drive source, and the linear motor is structured such that the movable element is supported in a fixed manner and the stator moves.
The features mentioned above and the other features of the present invention will be described below.